A new look at the remains of Palestinian leader Yasser Arafat could potentially reveal evidence of poisoning in the 8-year-old remains, but the investigation may be tricky, experts say.

Arafat's remains were exhumed from his grave in the West Bank on Nov. 27 so that samples could be taken and tested, according to news reports. The exhumation was called for after a Swiss laboratory said it found traces of polonium, a radioactive element and poison, on Arafat's clothing.

To test for polonium poisoning, a medical examiner would prefer to use samples of blood and bile, but these fluids will have disappeared from Arafat's body after so many years, said Dr. Jane Turner, an associate professor of pathology at Saint Louis University School of Medicine, and a medical examiner for the city of St. Louis, Mo. However, examiners could use hair samples or tissue from organs, if they are well-preserved, to look for polonium, Turner said.

While levels of polonium in a body would be high shortly after poisoning, they would have decreased with time, Turner said.

But even if investigators find traces polonium, it doesn't prove that poisoning killed Arafat — the element could have found it's way into the body by other means, Turner said. For instance, the element can be found in soil, which may have contaminated the remains.

Polonium is also in tobacco, and so smoke residue on clothing could also turn up false readings, Turner said.

For these reasons, it would be important to review Arafat's medical records to see if he showed symptoms of poisoning, such as a low white blood cell count, loss of hair and vomiting, Turner said.

"It will be interesting to see how the investigation ties all of these factors together," to either support or refute the poisoning allegation, Turner said.

Records show Arafat died of a stroke related to infection, but the infection was not identified, according to news reports.

Infections are usually pretty apparent at the time of autopsy, Turner said, but it's possible to miss evidence of poisoning if investigators had not thought to check for a particular poison, she said.

"You have to know what the chemical is you're looking for, in many instances," Turner said.

Investigators could also examine the organs, including the kidney and heart, for signs of natural diseases, such as hypertension and diabetes. If investigators find evidence of natural disease, but no evidence of poisoning, "it's more difficult to clearly state that there was some kind of poisoning," Turner said.